<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 以上3个meta标签，必须放在前面 -->
    <title>Bootstrap 导航条</title>

    <!-- Bootstrap -->
    <link href="css/bootstrap.min.css" rel="stylesheet">

    <!-- jQuery -->
    <script src="js/jquery.min.js"></script>
    <!-- 加载 Bootstrap 的所有 JavaScript 插件，也可以加载单个插件 -->
    <script src="js/bootstrap.min.js"></script>
    <style>

    </style>
</head>
<body>

<nav class="navbar navbar-default">
    <div class="container-fluid">
        <div class="navbar-header">
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#">
                <span class="sr-only">Toggle navigation</span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            </button>
            <a class="navbar-brand" href="#">Brand</a>
        </div>

        <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
            <ul class="nav navbar-nav">
                <li class="active"><a href="#">Link <span class="sr-only">(current)</span></a></li>
                <li><a href="#">Link</a></li>
                <li class="dropdown">
                    <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true"></a>
                </li>
            </ul>
        </div>
    </div>
</nav>

</body>
</html>